If we’re serious about Predator Free 2050—about ridding New Zealand of every last rat, stoat and possum—then Fiordland poses its sternest backcountry test. If we can pull it off here, we can pull it off in any of our national parks. What makes this land so difficult—and so important?

As things stand, the land can’t endure our enterprise much longer. If it’s to sustain our grandchildren, we have to change the way we think and cultivate. The Our Land and Water National Science Challenge is helping us forge a new accord with the soil beneath our feet.

There isn’t a catch limit on the lucrative whitebait fishery, which threatens to extinguish a cherished tradition and a small family of fish in one sweep of the net. If nothing changes, two whitebait species will be gone within five years, and the rest by 2034.

Twice the kākāriki karaka has returned from the dead. Orange-fronted parakeets were declared extinct in 1919 and again in 1965, but each time, the birds were concealed deep in the beech-forested valleys of Nelson and Canterbury. Now, the bird is approaching its third extinction, and this time, rangers have already scoured the valleys for hidden strongholds. This time, there isn’t a secret population waiting in the wings.

Every summer, a plague of wasps gathers, ruining picnics, harassing trampers and disrupting ecosystems. Wasps outcompete bees for food, costing New Zealand about $130 million each year in loss of honey and pasture crops. Where wasps abound, biodiversity suffers: butterflies disappear, songbirds stop breeding and invertebrate communities are looted. But there’s hope on the horizon. Scientists are developing weapons, both biological and genetic, in a bid to cure the pestilence, once and for all.